Well, I totally disassembled the reservoir and sand blasted it before repainting with black primer. It was reassembled dry, with a new neoprene washer for the clutch tube. The short feed lines to the master cylinders were bead blasted and blown clean for several minutes. No chance of any fluid left, but there is a slim possiblity of a stray glass bead or two. I filled the reservoir with the outlets capped and let it sit overnight to check for leaks...then intalled it and bled everything down.
Really, those are the only items that held the fluid prior to the leak. If a clean start is possible, then this was it. It did sit for 2 weeks leaking before I discovered it yesterday.
It has to come down to the PPG I used. All I can even think is that I sprayed it in 60 degree weather...colder than I usually spray...but still within specs. What it amounts to, though, is the silicone is definitely BETTER than glycol fluid...but it is possible some paint will be affected by it. Should've used Glasurit!